v3.8.0.1
Acquisition of subsidiary and deposits paid for acquisition of subsidiaries (Purchase Price Allocation) (Details)
$ in Thousands, $ in Millions
 1 Months Ended 12 Months Ended
Dec. 22, 2017
USD ($)
Dec. 22, 2017
HKD ($)
Dec. 31, 2016
USD ($)
Dec. 27, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 28, 2015
USD ($)
Dec. 31, 2017
USD ($)
May 10, 2017
USD ($)
Mar. 31, 2016
USD ($)
Total purchase price comprised of:                  
cash consideration           $ 52,000 $ 11,000    
Amortizable intangible assets                  
Goodwill     $ 36,504   $ 0   $ 49,977    
Boca International Limited [Member]                  
Total purchase price comprised of:                  
cash consideration         52,000        
share-based consideration         4,080        
Total         $ 56,080        
Amortizable intangible assets                  
Goodwill           $ 36,504     $ 36,504
Deferred tax liabilities                 (6,638)
Boca International Limited [Member] | Backlog Contract [Member]                  
Total purchase price comprised of:                  
Net liabilities acquired                 (337)
Amortizable intangible assets                  
Amortizable intangible assets [1]                 372
Boca International Limited [Member] | Proprietary Technology [Member]                  
Amortizable intangible assets                  
Amortizable intangible assets [1]                 $ 26,179
Century Skyway Limited [Member]                  
Total purchase price comprised of:                  
cash consideration     32,600 $ 35,000          
share-based consideration     2,325            
Total     $ 34,925            
Net liabilities acquired               $ (67)  
Amortizable intangible assets                  
Goodwill                
Deferred tax liabilities               (4,920)  
Century Skyway Limited [Member] | Proprietary Technology [Member]                  
Amortizable intangible assets                  
Amortizable intangible assets               $ 19,682  
Giant Connection Limited [Member]                  
Total purchase price comprised of:                  
share-based consideration $ 2,354                
Total 2,354 $ 19.6              
Net liabilities acquired 2,113                
Amortizable intangible assets                  
Goodwill 248                
Deferred tax liabilities $ (7)                
[1] Acquired amortizable intangible asset-backlog contract and proprietary technology have estimated amortization periods of one year and twenty years, respectively.